Reconfigurable devices whose functions and properties can be altered in response to an external input stimulus are of considerable interest in a variety of fields. Without limitation, devices in which reconfigurable characteristics can be desirable include, for example, coatings, sensors, electronic media and the like. Most often, reconfigurable devices can be made to be reversibly reconfigurable, such that the normal operational state of the device is restored once the input stimulus is removed and the properties of the altered operational state are no longer needed. However, irreversible reconfiguration can also be desirable for certain types of devices. Although a variety of reconfigurable devices have been developed, there is still an ongoing need to further develop this technology.
Anti-tampering devices, in particular, are a class of devices that can benefit from having reconfigurable characteristics. Tampering of industrial devices, particularly in the electronics industry, represents an ongoing challenge for manufacturers. As used herein, the terms “tamper” or “tampering” will refer to any unauthorized use, access or investigation of a device, whether malicious or not. At a minimum, tampering can sometimes result in the improper operation of or damage to a device. In other cases, a device can be modified in a manner that makes the device operate in a way that is inconsistent with that which its manufacturer intended. In this regard, a manufacturer may wish to have evidence that an unauthorized modification has occurred (e.g., for warranty validation purposes). Imparting tamper resistance to a device can also lessen the likelihood that unauthorized personnel can perform maintenance on the device.
An even more significant concern for manufacturers is the unwanted evaluation of a device and its components for reverse engineering or other malicious purposes. In such cases, a manufacturer may wish to temporarily or permanently change the operational performance of a device while it is being improperly examined or manipulated in order to prevent loss of valuable corporate knowledge.
Although a variety of systems to prevent tampering have been implemented in industrial devices, there is still an ongoing need to develop new anti-tampering paradigms. In this regard, it can generally be desirable for an anti-tampering system to resist tampering, detect when tampering has occurred or is occurring, respond to tampering, and to provide evidence of past tampering. However, it is not necessary that an anti-tampering system alert the tamperer that an anti-tampering system is in place.
In view of the foregoing, methods and systems for reconfiguring a device in response to an input stimulus would be of substantial benefit in the art. The present invention satisfies the foregoing need and provides related advantages as well.